Impulse
by Rhalei
Summary: Peter knows one thing for certain: the Stiff's brother isn't the dumbest Prior sibling.
1. Impulse

"You brought it on yourself, you know."

The second Stiff's voice is breathless, like he'd just run a marathon trying to get here (and perhaps he had, in his own right—Peter had seen the way he ran away from that train), echoing throughout the barn and forcing itself into Peter's earshot.

"Did I?" Peter almost snarls. He doesn't look back at him, but he knows Caleb is just standing there in the doorway, shifting awkwardly from foot to foot and fidgeting with his hands, like he does every fucking time someone addresses him.

The weakness radiating off of him is palpable.

"Yeah," Caleb says. "Yes—you did. Beatrice isn't—she doesn't cope the same way others do, she doesn't think—"

Peter can't help but flash a bitter smirk over his shoulder. The gash in his cheek is a helpful reminder of that. "So you admit to thinking your sister is impulsive and irrational? Wow, Caleb, way to sell out the only family you have left."

"That's not what I—"

"I think that's exactly what you meant," Peter murmurs, his eye twitching as he narrows them both in Caleb's general vicinity, a predator sizing up his prey. He notices the way Caleb's jaw tightens, and the lump he swallows down his throat, and the doe-eyed look of intimidation widening brown eyes with every step Peter takes closer, and for some strange reason, he's spurred on by it. "Why so reluctant to admit it? Don't you think your parents agree with you?"

Peter's half-expecting him to cry, or go off into a tangent about what a vile and despicable creature Peter Hayes is (it wouldn't be the first time he's heard it), but he doesn't. He stands there, and he shakes his head, and for a split second Peter fears that Caleb is too damn smart to be fooled by the mind games Peter's trying to play.

But fear isn't something that fazes him.

"I'm not my sister," Caleb says—carefully. His voice is trembling. "If you're trying to get a rise out of me, you're not going to get one."

Peter stares at him for a little while, lips stretching into a lopsided smirk. And all of the sudden, he reaches out to seize Caleb by the throat, putting the slightest amount of pressure on either side of his Adam's apple. The action draws no more than a gasp and a flinch out of Caleb, his pupils blown wide and his mouth agape—but alas, no attempt at self defense. Peter can't tell if this is cowardice or simply a testament to Caleb's advantage over his less-fortunate sister in the intelligence department.

Peter chuckles.

"Is this why you're the smart one?" He asks.

"Maybe," Caleb breathes.

That's when Caleb licks his lips. Maybe because they're going dry with how fast he's breathing, or maybe because Peter wasn't imagining things when he caught his gaze flickering down to Peter's mouth just now. _Maybe_ is irrelevant to him.

Peter crushes his lips against Caleb's, and Caleb whimpers, and in that moment, both of them stop thinking.


	2. Instinct

**A/N: Rated T for brief mentions of sexual conduct.**

* * *

"Did you mean it?"

Caleb sits with his back against a few stacked bundles of hay, the first few buttons of his shirt popped open, his face flushed, his skin glistening with a light layer of sweat. If Peter were chowing down on the drug-infused hippie bread the Amity are so fond of, he might have done a double take when his gaze wandered over to the other boy. Might have thought he was looking at some god in the form of a clumsy beanstalk of a boy.

But Peter isn't high, and he's now shimmying back into his trousers, furrowing his brows with confusion at Caleb's question. "Mean what?"

"What you said to Beatrice." He pauses for a moment and draws his bottom lip through his teeth, then continues. "About staying here with me. I know you were just trying to…to rile her up, but it was an oddly specific way of—"

"If anybody here knows how to press a Stiff's buttons, it's me," Peter grumbles. "I was just putting her back in her place. Don't get full of yourself."

It's the truth. It's the full, honest truth, and though he's lied plenty of times before, as a born Candor it's wired in his brain to tell the truth. So why does it feel like a lie? Why does it make him uncomfortable to see Caleb swallow thickly and train his gaze on the ground? Why didn't he go for Four, why didn't he tell the Stiff he'd keep an eye out for her boyfriend so she didn't get him put under crazy serum again?

In the midst of his internal debating, Caleb decides to speak up again, the semblance of a playful smirk on his swollen lips as he eyes the wound on Peter's cheek (it's scabbing over now and Peter still hates when Caleb focuses his attention on it). "I don't think you succeeded."

Peter falters for approximately half a second before pulling a brown jacket over his top, pointing a finger at him despite the grin that mirrors the smug expression on Caleb's face. "Actually, I made her crack and finger-banged her brother for a steady half an hour, so I win."

Caleb stops smirking after that.

Peter's fully dressed in no time, his hair sloppily molded back into place with a generous amount of saliva and the palm of his hand. He doesn't want to have to look at the Stiff. He doesn't want to hear a lecture from her manchild bodyguard. He doesn't want the weird Amity lady to send him out into the wilderness to fend for himself. He wants to stay here, give himself a second to breathe, trace his fingertips possessively along Caleb's side and drill him about how the hell someone who's never so much as been kissed before makes the noises he just did.

He sits down beside Caleb with a grunt, offering a snort at the way his cheeks are still tinged bright red. "So why'd you leave Erudite?"

"Hm?" Caleb's response is quick and eager—he's been dying to change the subject.

Peter scratches at his ear. "Someone all…smart and floppy like you, you don't seem like the type of person who's ready to fight in a rebellion."

He anticipates offense at the statement, but he doesn't get any. Caleb's still calm. His gaze is still burned into the ground. His lips part slightly to allow a deep breath in.

"I'm not. At least, not physically. Maybe not mentally, either, I don't…I don't know," he murmurs. "When I left, I left because they were going to kill my parents—I was all in favor of the Erudite taking over the government, not committing mass genocide to get there."

Peter squints as he nods, noting the uncertainty to his tone. "You don't really understand how people work, then. Do you?"

There's a brief moment of silence before Caleb glances up at him with sad, glistening eyes, like a kicked puppy, giving a slow shake of his head. Peter feels like he's just been injected with poison that tastes like candy. Finally, he raises his brows and smoothes out the fabric of his pants as he sits up, glancing back at Caleb and slinging an arm over his knees.

"Well, Caleb, you want my advice?" He doesn't wait for an answer. "That whole scampering away when danger strikes thing you've been doing? Keep doing it. Duck to dodge the bullets and stay the fuck out of the way when somebody starts flinging a weapon at you, you're not trained enough to fight back and your reflexes are shitty."

"Peter—"

"I know it doesn't seem like it now, but shit is gonna hit the fan soon. I mean, it's bound to, what with crazies like your sister declaring war on the factions and threatening to assassinate Jeanine. And when that happens, you can bet your ass I'm not gonna be around to protect you all the time and stay at your side to make sure Tris doesn't get you killed. So—you be smart, okay?"

By the time he's finished speaking, he's breathless, biting hard into the inside of his lower lip and holding Caleb's stare until it feels uncomfortable again. Caleb's got this look in his eyes, like he doesn't know whether to trust him, whether to speak or just nod his head or cry or protest or ask Peter to stay with him. Peter isn't even sure which outcome he wants anymore.

"Okay," he whispers. "I just—"

Peter doesn't wait for him to say something self-deprecating again, instead surging down to kiss him roughly, kiss him slowly, pour everything he can't say with words into his actions, make Caleb feel how much he wishes he didn't care about him. His hand settles on Caleb's jaw and it keeps him close as he opens his mouth with his own and slips his tongue past the barrier of his lips. He wants to corrupt him, and save him from himself, and spend hours every night in a rundown barn running his hands along every curve of his bare body and whispering dirty things in his ear. He can't, though. In his heart of stone-cold hearts, he knows he can't.

Just as Caleb's arms find a way around his neck, Peter stops, his breathing ragged as his gaze flickers frantically across Caleb's face. And like that he pulls away, he untangles himself from Caleb's arms and legs and stumbles to stand up, ignoring the soft sound of protest the other makes to send a look of resignation his way. He's looking out for him, he thinks. Protecting him. How nice of him.

"I'll see you later, Prior," he mumbles.

As it turns out, after that evening a "see you later" is all he has left to hold onto.


End file.
